Presently, many upper extremity prosthetic devices are custom made. In a typical manufacturing process, a cast is made of the amputee's residual limb. A prosthetic device is then molded from the casting. This process is time-consuming and costly. It further requires highly trained individuals to build and fit the devices. As a result, persons with low income and people in most developing countries have no access to such custom fitted devices much less the ability to pay for such devices. Thus, many people are deprived of the benefit of a prosthetic device. In addition, even those persons who can afford an expensive, customized prosthetic device do not participate in a wide variety of activities, such as sporting events, due to concerns over damage to their prosthetic device.
One example of an upper extremity prosthetic device is disclosed in the U.S. Pat. No. 5,888,235. The invention is a prosthetic arm mountable on a socket attached to the residual limb of a person. The prosthetic arm includes a base for attachment to the socket, a forearm section or adapter having a proximal end and a distal end, a terminal device such as a hook or anthropomorphic hand, and attached to the distal end of the forearm section or adapter for selectively opening or closing. An elbow joint interconnects the proximal end of the forearm section to the base, the elbow joint being pivotable to enable moving the forearm section upwardly or downwardly. Control straps and cables fitted on the person are responsive to body movements of the person for selectively locking the elbow joint to prevent it from pivoting while allowing the terminal device to open or close or locking the terminal device to prevent it from opening or closing while allowing the elbow joint to pivot.
Another example of a prosthetic arm is disclosed in the U.S. Patent Application Publication No. 20070213842. This invention comprises a forearm section adapted to mount to the arm of a patient, a hand section including a thumb and at least one finger, and a wrist section connected between the forearm section and said hand section. Movement of the prosthesis is achieved by a combination of pressurized air bladders and return springs. The prosthetic device is structurally and functionally interconnected to simulate a large number of the movements performed by the corresponding natural skeletal structures.
Although there may be a number of differing constructions for arm prosthetic devices, there is still a need to provide an upper extremity prosthetic device that is adjustable to fit persons of different sizes, provides an adjustable fit for a wearer over time, yet provides superior ability for the device to act as a functional prosthesis. There is also a need to provide a prosthetic device for the arm that is relatively inexpensive, yet provides a comfortable and durable solution for the amputee. There is yet another need to provide a prosthetic device that is non-obtrusive to the amputee and provides a natural appearance of a substitute limb.